Trouble Posting

HI everyone,
I recently upgraded from 2.5 to 2.5.1 and once I did, I have had a hard time posting anything. It will say “your attempt to edit this post has failed. Please retry.” Well, when I go to manage posts and click on that one, only the subject line has any words. The body of the post is blank.

When I am writing the post, when it says it’s “saving draft”, it appears to take forever, but then does not save it. When I first click on “write a new post”, it takes so long to download that page and sometimes it does not download correctly.

Is this a problem with my host or did I screw something up when I upgraded (because that is definitely a possibility ;)) from 2.5 to 2.5.1? Please help!